Resilient floor tile and method of making same

ABSTRACT

A resilient floor tile is described that comprises a base; a protective film layer; and a decorative layer disposed between the base and the protective film layer; wherein the resilient floor tile has a top surface and a convex edge along a perimeter of the top surface. In another embodiment, the resilient floor tile comprises a decorative layer comprising a printed ink forming a decorative pattern disposed between a base and a protective film layer; wherein the decorative pattern extends over at least a portion of a contoured edge of the tile such that the decorative pattern is substantially undistorted. The process for making a resilient floor tile comprises preheating a printed tile blank; cutting and molding the printed tile blank concurrently to form a resilient floor tile having a convex edge along a top, outer perimeter of the resilient floor tile.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to floor tiles. More specifically, theinvention is directed to a resilient floor tile having a contoured edgeand a method for making the same.

2. Description of Related Art

Resilient floor coverings are produced in the form of a continuous sheetor in the form of a tile, such as a vinyl composition tile. Typically,resilient floor tiles are installed in a butt-fit arrangement, whereinthe side of each tile is in physical contact with the sides of adjacenttiles. The tiles are secured to the subfloor through the use of anadhesive; however, there is typically no filler or adhesive used betweenthe adjoining sides of the tiles. As such, one disadvantage of this typeof installation is the presence of gaps or openings at tile joints,which may result from an uneven cut along the side of a particular tileduring manufacture, an uneven subfloor or thermal contraction of thetiles. Another disadvantage of this type of tile and installation ismaintaining each tile at the same height on the floor as the tilesadjacent to it. If one tile is slightly higher than an adjacent tile, a“step” is created between these tiles, which may result in chipping orbreakage of the tile portion that is higher than the surface of theadjacent tile. In addition, the side of the tile that extends above theadjacent tile surface may also act to trap dirt along that side, whichis typically difficult to remove.

Regardless, attempts have been made to manufacture and install resilientfloor tiles to simulate the appearance of ceramic tiles or naturaltiles, such as stone tiles, including marble, slate and granite, all ofwhich are typically more expensive than a resilient tile floor. Forexample, resilient tiles may contain a decorative ink pattern tosimulate the surface appearance of ceramic or natural tiles, or they maycontain other decorative elements, such as small particles, to similarlysimulate the appearance of ceramic or natural tiles. Additionally, someresilient tiles are embossed to simulate the grout that is used betweenceramic and natural tiles when installed as a flooring. However, theseattempts have never quite matched the appearance of a ceramic or naturaltile nor the appearance of a flooring having grout between such ceramicor natural tiles.

One might consider installing existing resilient floor tiles with grout;however, there are several disadvantages to this due mainly to thesquare edge of the resilient floor tile. First, the square edge wouldmake it difficult to properly place the grout between the tiles so thatthe grout does not pull out as additional grout is laid. Second, groutwill typically shrink in size such that the top of the grout would bebelow the top surface of adjacent tiles, making the exposed verticaledge of the tile more susceptible to damage and collection of dirt alongthis edge. Also, particles may be dislodged from this edge by foottraffic and dragged across the top surface of the tile, therebyabrading, marring or scuffing its surface.

Some resilient floor tiles have been made with a beveled or flat,slanted edge. However, in these cases, when the beveled portion is cut,the underlying substrate is exposed, which requires additionalprocessing to cover it up. For example, a paint or coating must beapplied to cover this exposed area, which may be a different color fromthe top surface, thereby failing to simulate a natural stone or ceramictile appearance, which has a consistent color across its surface. Whilethese tiles are typically installed in a butt-fit arrangement, if groutwere used the flat surface of this beveled portion will most likelyresult in the same difficulty in installing the grout as with asquare-edged tile since the edge where the beveled portion meets thevertical side wall of the tile will still be a sharp edge.

Therefore, there is a need for a resilient floor tile that in use moreclosely simulates the appearance of a ceramic or natural tile and thatcan allow for installation using grout.

SUMMARY OF THE INVENTION

A resilient floor tile and method for making the same are described. Inone embodiment, the resilient floor tile comprises a base; a protectivefilm layer; and a decorative layer disposed between the base and theprotective film layer; wherein the base, the protective film layer andthe decorative layer form a resilient floor tile having a top surfaceand a convex edge along a perimeter of the top surface. In anotherembodiment, the resilient floor tile comprises a base; a protective filmlayer; and a decorative layer comprising a printed ink forming adecorative pattern disposed between the base and the protective filmlayer; wherein the base, the protective film layer and the decorativelayer form a resilient floor tile having a top surface and a contourededge along a perimeter of the top surface and wherein the decorativelayer extends over at least a portion of the contoured edge such thatthe decorative pattern is substantially undistorted.

The process for making the resilient floor tile comprises preheating aprinted tile blank; cutting the printed tile blank; and molding theprinted tile blank to form a convex edge along a top, outer perimeter ofthe printed tile blank; wherein the cutting and molding are performedconcurrently to form a resilient floor tile.

The convex edge of the present invention provides for an surprisinglypleasing simulation of ceramic and natural tile floors, such as stonetile floors, including, marble, slate and granite. The convex or roundededge allows for installation of the resilient floor tile using grout,whereas tiles having a square edge make grout installation difficult. Inaddition, a convex edge allows for easier cleanability of the grout andthe edge of the tile itself, as compared to a tile having a right angleedge that may have dirt embedded in the exposed vertical side. Further,the print layer extends over the surface of the convex edge, therebyalleviating the need to further print a decorative pattern on what wouldotherwise be an exposed surface after cutting of a contoured edge alongthe perimeter of the tile.

Other features of the invention will appear from the followingdescription in which the preferred embodiments are set forth in detailin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view taken along line A-A of FIG. 2 of aresilient floor tile according to one embodiment of the presentinvention;

FIG. 1B is a cross-sectional view of a resilient floor tile according toanother embodiment of the present invention;

FIG. 2 is a top view of the resilient floor tile of FIG. 1A;

FIG. 3 is a partial plan view of a flooring made with resilient floortiles according to one embodiment of the present invention;

FIG. 4 is a partial plan view of a press and die according to oneembodiment of the present invention;

FIG. 5 is a bottom view of an upper die plate according to oneembodiment of the present invention;

FIG. 6A is a partial plan view of a die at a first operating positionaccording to one embodiment of the present invention;

FIG. 6B is a partial plan view of the die of FIG. 6A at a secondoperating position according to one embodiment of the present invention;and

FIG. 7 is a process flow schematic of a process for making a resilientfloor tile according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The structure and function of the preferred embodiments can best beunderstood by reference to the drawings, which are described below. Itshould be noted that where the same reference designations appear indifferent figures, the numerals refer to the same or correspondingstructure in each of those locations.

FIG. 1A shows a cross-sectional view taken along line A-A of FIG. 2 of aresilient floor tile according to one embodiment of the presentinvention. Resilient floor tile 100 is a composite, laminated structurethat comprises a base 102, a decorative layer 104 disposed on top of thebase 102, a protective film layer 106 disposed on top of the decorativelayer 104, a top coat 108 disposed on top of the protective film layer106, and a bottom coat 110 disposed on the bottom side of the base 102.The resilient floor tile 100 also has a top surface 112 that, in use, isthe surface of the resilient floor tile 100 exposed to the environmentor foot traffic.

It should be appreciated that “resilient floor tile” refers to thosefloor tiles that are synthetic or man-made and that have a certaindegree of resiliency or flexibility. Materials useful in making aresilient floor tile may include organic materials, such as polymericmaterials, including, for example, vinyl or mixtures of organic andinorganic materials. Accordingly, the base 102 may be made of anymaterial useful in making a resilient floor tile. For example, the basemay be a mixture of limestone and a polymeric resin and may also includeplasticizers and pigments. More specifically, the polymeric resin may bea copolymer or a homopolymer. Specific examples of base compositionsinclude a vinyl composition that includes limestone, acetatepolyvinylchloride resin, plasticizer and, optionally, pigments, wherethe organic materials function as a binder for the limestone.Alternatively, the base may be a vinyl composition that includeslimestone, polyvinylchloride homopolymer, plasticizer and, optionally,pigments, where the organic materials also function as a binder for thelimestone.

It should be appreciated generally that the base contributessignificantly to the overall flexibility of the resilient floor tile.Again, while any material may be used as the base, it is preferred thatthe base composition and, therefore, the overall resilient floor tilehave some rigidity and not be completely flexible such as a rubber tileor solid vinyl tile. Since the binder content of the base affects thelevel of rigidity of the overall resilient floor tile, it is preferredthat the total organic content or binder content of the base be lessthan approximately 34% by weight, more preferably approximately 20% orless by weight, approximately 18% or less by weight, or approximately17% or less by weight. Binder contents such as approximately 26% byweight or approximately 28% by weight may also be used.

While the base 102 is shown in FIG. 1A as having a significantly greaterthickness than the other layers of the resilient tile 100, it should beappreciated that the thickness of the base 102 may be any desiredthickness, and the relative dimensions shown in FIG. 1A are not intendedto be limiting. Preferably, however, the thickness of the base 102 issuch that it provides most of the structural rigidity to the resilientfloor tile 100. More preferably, the thickness of the base 102 isapproximately 50-200 mils. A preferred thickness for the entireresilient floor tile 100 is approximately 4 mm.

The decorative layer 104 is disposed on top of the base 102. Thedecorative layer 104 is any layer that provides a decorative pattern ordesign to the resilient floor tile 100. In its simplest form, thedecorative layer may be a printed ink pattern that provides a decorativepattern or design. Alternatively, the decorative layer 104 may be aplurality of particles or chips of various solid materials, such aswood, textiles, metals or plastics that are disposed on top of orembedded in the top of the base 102. Preferably such particles or chipswill adequately adhere to the base; however, an adhesive may be used ifnecessary. More preferably, such particles or chips comprisepolyvinylchloride chips. It should be appreciated that the decorativelayer may not be a continuous layer that covers the entire top surfaceof the base. For example, where the decorative layer comprises an inklayer that forms a decorative pattern on the base, the ink itself maynot cover the entire top surface of the base, as it will only be onthose portions of the base required to make the decorative pattern.

It should be appreciated that while the decorative layer 104 is shown inFIG. 1A as being disposed on top of the base 102, the decorative layermay actually be disposed anywhere between the base and any other layerin the resilient floor tile. For example, a top-print film may be used(not shown). In this case, the decorative layer would be an ink layerthat provides a decorative pattern or design that is printed on one sideof a film, preferably a polymeric film, such as polyvinylchloride. Thistop-print film is placed on the base with the printed ink side facingup, such that the film itself would be disposed directly on top of thebase. In this case, an additional film layer, the top-print film, wouldbe disposed between the base and the decorative layer or printed inklayer. Typically, such top-print film has an approximate thickness of1.5-2 mils. Using a top-print film allows for the decorative layer to beprinted on the top-print film before being placed on the base, whichavoids having to print ink directly onto the base. Such printing may bedone through the use of transfer paper.

It should be appreciated that the relative thickness shown in FIG. 1Afor the decorative layer 104 is only for illustrative purposes andshould not be considered limiting. The decorative layer 104 may be anydesired thickness but in the case of printed ink, it is preferablyapproximately 0.5 mils. Therefore, in combination with a top-print film,the total thickness would be approximately 2-2.5 mils.

The protective film layer 106 is a film that is disposed on top of thedecorative layer 104. The protective film layer 106 is preferably apolymeric film and is used to protect the decorative layer once theresilient floor tile 100 is placed in use. For example, the protectivefilm layer 106 may be used to protect the decorative layer 104 fromscuffing, marring and abrasion caused by wear or foot traffic on theresilient tile 100.

The protective film layer 106 may be, for example, a cap film, which isa polymeric film, such as a polyvinylchloride film. Such a cap film maybe disposed directly on top of a decorative layer comprising either aprinted ink decorative pattern or on top of a decorative layercomprising a plurality of particles or chips disposed on the base.

Alternatively, the protective film layer may be a back-print film. Aback-print film is a film having a printed ink pattern that provides adecorative pattern or design on a bottom side of the back-print film.This back-print film is positioned on top of the base with the printedink pattern facing the base of the tile. The printed ink pattern thenbecomes the decorative layer of the resilient floor tile, and theback-print film itself acts as the protective layer to protect theprinted ink or decorative layer when the tile is used. This avoids theuse of a separate protective layer as would otherwise be used with atop-print film. Similar to a top-print film, however, a back-print filmallows for the decorative layer to be disposed on the top-print filmbefore being placed on the base, which avoids having to print inkdirectly onto the base.

It should be appreciated that the relative thickness shown in FIG. 1Afor the protective film layer 106 is only for illustrative purposes andshould not be considered limiting. The cap film 106 may be any desiredthickness but preferably is approximately 3 mils.

It should be appreciated that the use of a protective film layer isoptional. In other words, a protective film layer, such as a cap film orback-print film, is not required in the present invention. In someembodiments of the present invention, the protective film layer may bethe top layer or exposed layer of the resilient floor tile. In suchcases, floors made using such resilient tiles would typically requirewaxing to maintain the appearance of the resilient tile.

The top coat 108 is disposed on top of the protective film layer 106.Typically, the top coat 108 comprises a polymeric film, such as aurethane film that is cured using ultraviolet radiation, that isdesigned to protect the protective film layer 106 and the decorativelayer 104. In one embodiment, the top coat 108 is used to avoid waxingof the resilient floor tile in use. In other words, the use of a topcoat generally makes the resilient tile a “no-wax” floor tile. The topcoat 108 may also comprise additional components, such as particles,including, for example, aluminum oxide or nylon particles, and it mayhave visible texture. Various top coats that may be used in the presentinvention are described in U.S. patent application Ser. No. 09/765,713,entitled “Coating Having Macroscopic Texture and Process for MakingSame,” filed on Jan. 19, 2001, which is incorporated herein by referencein its entirety.

It should be appreciated that the top coat may also act as theprotective film layer, for example, in those cases where a top coat,which may comprise a urethane film, is placed directly on the decorativelayer without the use of a separate protective film layer. It shouldalso be appreciated, however, that the use of the top coat 108 isoptional. Further, although not preferred, the decorative layer may beexposed, which obviates the need for both a protective film layer and atop coat.

Generally, any layer disposed on top of the decorative layer 104 may beused to protect the print layer. Such a protective layer mayalternatively be referred to as a “wear layer.” Therefore, both theprotective film layer 106 and the top coat 108 may each be referred toas a “wear layer” or may be collectively referred to as a “compositewear layer.”

The bottom coat 110 is any layer disposed on the bottom of the base 102.Typically, the bottom coat 110 comprises a polymeric film and isdesigned to maintain the integrity of the base 102 and of the overallresilient floor tile 100, particularly upon application of the otherlayers on top of the base 102. Application of these other layers on topof the base 102 may result in stress forces that tend to curl or pullthe edges of the tile upwards. To counter these forces, the bottom coat110 may be used. It should be appreciated, however, that use of thebottom coat 110 is optional.

As shown in FIG. 1A, a novel aspect of the present invention is theconvex or rounded edge 114 of the resilient floor tile 100. It should beappreciated that this convex edge 114 is located at the top of theresilient tile 100, as opposed to the bottom, and extends around theentire perimeter of the top surface 112 of the resilient tile 100. Itshould be appreciated that reference to the top surface of the resilienttile 100 refers simply to the top, exposed surface of the tile,regardless of what layer is actually on top. For example, the topsurface could be the top of the protective film layer or the top of thetop coat, if present.

The convex edge 114 is also contiguous with the vertical side wall 116of the resilient floor tile 100, which is that portion of the side ofthe resilient tile 100 that extends from the convex edge 114 to thebottom of the resilient tile 100. In other words, where the curvature ofthe convex edge 114 ends, the vertical side wall 116 begins andcontinues to the bottom of the resilient floor tile 100.

As will be discussed below, it should be appreciated that this convexedge 114 is typically formed after the base 102, the decorative layer104 and the protective film layer 106 have been put together. As aresult, as shown in FIG. 1A, both the decorative layer 104 and theprotective film layer 106 extend over at least a portion of the convexedge portion 114 and preferably over the entire curvature of the convexedge 114. A further novel aspect of the present invention is that thedecorative pattern provided by the decorative layer 104 that extendsover the convex edge portion is substantially undistorted. For example,in the embodiment where the decorative layer comprises a printed inkthat forms the decorative pattern, this decorative pattern appears tohave little or no visible distortion as it extends over the convex edgeportion. In this manner, the decorative pattern remains visible andvisually pleasing on the top surface 112 as well as along the convexedge 114 as it extends over the side of the resilient floor tile 100.

It should be appreciated that the convex edge 114 may have any arc orradius of curvature desired. In any case, the print layer 104 and thecap film 106 will extend over at least a portion of the convex edge 114,and, preferably, over the entire curvature of the convex edge 114. Inother words, with a curvature having a larger radius or arc, the convexedge 114 will have a greater surface area and will extend furthertowards the bottom of the resilient floor tile before becoming integralwith the vertical side wall 116. In this case, it is preferred that theprint layer 104 extend over this larger surface area of the convex edge114 to cover the entire surface area of the convex edge from the topsurface 112 to the point where it becomes integral to the vertical sidewall 116. Similarly, a smaller radius or arc would allow for a smallercurved edge having a smaller surface area and a correspondingly highervertical side wall. It should be appreciated that, generally, the layerson top of the print layer may extend over the convex edge to a lesserextent than the underlying print layer. It should also be appreciatedthat it is not necessary for the print layer to extend over the entiresurface area of the convex edge. In other words, the print layer willextend along the entire length of the edge or side of the resilientfloor tile but may only cover a portion of the convex edge from the topsurface to the point where it becomes integral to the vertical sidewall.

It should further be appreciated that the convex edge 114 is just oneexample of the type of edge that may be used on the tile. The edge mayinclude other contours or shapes, such as a flat, beveled edge. Althougha convex or rounded edge is more preferred for use in installing theresilient floor tiles of the present invention with grout, thedecorative layer and decorative pattern may still be disposed over anedge having other contours, such as a beveled edge, so as to not distortthe decorative pattern.

It should also be appreciated that the side wall 116 is substantiallysolid, meaning that while it may have imperfections, such as cracks orsmall holes, it does not have any pre-formed openings or openings ofpredetermined shapes and sizes that may be used for other purposes, forexample, to accept interlocking male portions from adjacent tiles.Further, the side wall 116 does not have to be perfectly vertical orflat, particularly if the resilient floor tile 100 is to be installedusing grout. Such an installation has the advantage of accommodatingimperfectly-shaped side walls.

FIG. 1B is a cross-sectional view of a resilient floor tile according toanother embodiment of the present invention. While FIG. 1A has beendescribed as having multiple layers on top of a base, FIG. 1Billustrates another embodiment of the present invention, which is aresilient floor tile 150 having only a base 152 with particles or chips154 dispersed throughout that provide a decorative effect on the topsurface 156 of the tile 150. (Only a few of the chips 154 are labeled inFIG. 1B.) These chips 154 may be selected from various solid materials,such as wood, textiles, metals or plastics, such as thermoplastic orthermoset polymers including, for example, homopolymers or copolymers,specifically, for example, vinyl acetate resins or polyvinylchloride,and may have different colors ranging from white to dark. Further, thenumber of chips 154 used may vary. While FIG. 1B illustrates a resilientfloor tile made using a significant number of chips such that each chipis compressed against another chip, a much lower concentration of chips154 may be used. In this latter case, obviously the base will contain ahigher concentration of, for example, limestone.

The resilient floor tile 150 has convex edges 158 that extend around itsperimeter at the top of the base 152. Similar to the embodiment of FIG.1A, it should be appreciated that any arc or radius of curvature of theconvex edges 158 may be used. Further, it should be appreciated that theedge may include other contours or shapes, such as a flat, beveled edge.The resilient floor tile 150 does not have any additional layers on top;however, it should be appreciated that additional layers may be added.For example, a protective film layer, such as a cap film, or a top filmthat acts as a protective film layer, may be disposed on top of the base152.

From the foregoing, it should be appreciated that any resilient floortile composition may be used in the present invention. For example,resilient floor tiles known in the art, such as any resilient floor tilebase having polyvinylchloride, may be used to provide a resilient floortile having a contoured edge, such as a rounded or convex edge. Further,any resilient floor tile construction may be used in the presentinvention, including the use of only a base, such as a base havingparticles or chips, or a base having multiple layers thereon.

FIG. 2 is a top view of the resilient floor tile of FIG. 1A. As shown inFIG. 2, the resilient floor tile 100 is square. Further, it is evidentfrom FIGS. 1 and 2 that the decorative layer 104, the cap film 106, thetop coat 108 and the bottom coat 110 do not extend beyond the perimeteror boundary of the base 102. In other words, the horizontal dimensionsof each layer are similar and are aligned with the perimeter of the base102. It should be appreciated, however, that the resilient floor tile ofthe present invention may be any shape, including, for example, round,oval, rectangular, triangular, a polygon having any number of sides, orany other shape. In these cases, each layer of the resilient floor tilewould have a substantially similar shape to every other layer, exceptwith respect to a decorative layer, which as described above willgenerally take the shape of the desired decorative pattern and may ormay not be a continuous or complete layer across the entire surface ofthe resilient floor tile. As shown, preferably, the shape of theresilient tile of the present invention is square. More preferably, theresilient tile of the present invention is 9″×9″, 12″×12″, 14″×14″,16″×16″ or 18″×18″. It should be appreciated from FIG. 2 that thecorners of the resilient floor tile 100 are square, although it is notnecessary that the corners be square.

FIG. 3 is a partial plan view of a flooring made with resilient floortiles according to one embodiment of the present invention.Specifically, FIG. 3 illustrates a flooring 300 installed usingresilient floor tiles made according to the present invention withgrout. For illustrative purposes, only two resilient floor tiles 100 areshown (individual layers of each tile are not shown); however, an entireflooring would obviously be made using any desired number of resilienttiles necessary to cover the flooring area of interest and with anyresilient floor tile made according to the present invention. FIG. 3shows the subfloor 302 and an adhesive layer 304 disposed between thebottom of each resilient tile 100 and the subfloor 302. It should beappreciated that any type of adhesive may be used, but, preferably,either a pressure sensitive adhesive or a wet-set adhesive, orcombination thereof, is used. Grout 306 is installed between theadjacent resilient floor tiles 100. As shown, the top level of the grout306 is below the top surface 112 of each of the resilient floor tiles100. The combination of the grout 306 being disposed below the topsurfaces 112 of each of the adjacent resilient floor tiles 112, eachhaving a convex edge 114, is what gives the flooring 300 the appearanceof a ceramic or natural tile floor, such as a stone, marble, slate orgranite.

It should be appreciated that the resilient floor tiles of the presentinvention may also be installed in a butt-fit arrangement, wherein eachtile is positioned physically against an adjacent tile. In thisinstallation, grout would not be used; however, the tiles would beadhered to the subfloor in the same manner by using an adhesive such asa pressure sensitive adhesive or a wet-set adhesive. A joint sealer maybe used, however, to fill any gaps or openings between adjacent tiles.

FIG. 4 is a partial plan view of a press and die according to oneembodiment of the present invention. In general, it should beappreciated that one of skill in the art is familiar with such pressesand how they are constructed and operated. Generally, the press 402comprises a base 404 and an upper moveable portion 406 that can be movedin an up and down motion by a hydraulic cylinder 408 along guideposts410. An upper die plate 412 is attached to the upper movable portion406, and a corresponding lower die plate 414 is attached to the base404. A knife 416 is attached to the upper die plate 412 about itsperimeter. It should be appreciated that FIG. 4 actually provides across-sectional view of the upper die plate 412 to illustrate thecurvature 420 of the upper die plate 412 and the cutting edge 420 of theknife 416. Therefore, as will be discussed in connection with FIG. 5,the curvature 420 and the knife 416 actually extend around the entireperimeter of the upper die plate 412.

Also shown in FIG. 4 are scrap ejector plates 417, which are eachsupported by springs 418. A representative resilient tile blank 422 isalso shown on top of the lower die plate 414. One of skill in the artwill appreciate that there are other components of the press 402 thatare not shown, such as a heater and temperature control system thatprovide for heating either or both of the upper die plate 412 and lowerdie plate 414 to a desired set point temperature.

FIG. 5 is a bottom view of an upper die plate according to oneembodiment of the present invention. The upper die plate 500 comprises acenter portion 502, which is generally a large block made of metal, andfour side portions 504 that are beveled and connected at each corner andto the center portion 502. Each side portion 504 is constructed to havea contoured surface 506 that upon pressing a resilient tile blank willimpart the desired shape to the edge of the tile. For example, thiscontoured surface 506 may be a concave surface that will impart a convexedge to the tile. Alternatively, the contoured surface 506 may be a flatangled surface that imparts a beveled edge to the tile. The upper dieplate 500 may also be construed with a plurality of holes (not shown) inthe center portion 502 to allow for the passage of air during pressing.

Also shown in FIG. 5, although not inherently part of the upper dieplate, is a knife 508. The knife 508 extends around the entire perimeterof the upper die plate 500, and as shown in FIG. 4 comprises a bevelededge that provides a sharp edge at its tip adjacent to the side portions504 of the upper die plate 500.

FIG. 6A is a partial plan view of a die at a first operating positionaccording to one embodiment of the present invention. FIG. 6Aillustrates the upper die plate 412 and the knife 416. It should beappreciated that FIG. 6A is actually a cross-sectional view of the upperdie plate 412 and the knife 416 to illustrate the curvature of the upperdie plate 412 and the cutting edge of the knife. Also shown are theresilient tile blank 422, the lower die plate 414 and the scrap ejectorplates 417 and their corresponding springs 418. In this first operatingposition, the resilient tile blank 422 has been loaded into the pressand is ready to be cut and molded.

FIG. 6B is a partial plan view of the die of FIG. 6A at a secondoperating position according to one embodiment of the present invention.In this second operating position, the upper die plate 412 has beenlowered using the hydraulic cylinder 408, thereby cutting the perimeterportions 602 from the resilient tile blank 422 and pressing theresilient floor tile blank 422 between the upper die plate 412 and thelower die plate 414. The compression forces imparted from the upper dieplate 412 and the stationary lower die plate 414 act to mold theresilient floor tile blank 422 and impart the curvature 420 of the upperdie plate 412 to the top edge of the resilient floor tile blank 422,thereby forming a resilient floor tile. In essence, this process cutsand molds the resilient floor tile blank concurrently.

When the upper die plate 412 is in the second operating position, thescrap ejector plates 417 are depressed. After the cutting and molding iscomplete, the upper die plate 412 is returned to its first operatingposition to begin the cycle again with a second resilient floor tileblank. Once the upper die plate is lifted from this second operatingposition to return to its first operating position, the scrap ejectorplates 417 return to their original position and hold the scrap or“frame” that has been cut and separated from the resilient floor tile.As will be discussed below, this enables removal and recycle of thisscrape or frame.

FIG. 7 is a process flow schematic of a process for making a resilientfloor tile according to one embodiment of the present invention. Theprocess 700 for cutting and molding a resilient floor tile according tothe present invention begins by using a pallet of resilient floor tileblanks. A blank is a resilient floor tile that has already beenconstructed but not cut into its final dimensions. One of skill in theart will appreciate the various methods for making resilient floor tileblanks and the various compositions and constructions of such resilientfloor tiles.

One preferred method for making a vinyl resilient floor tile isdescribed in U.S. patent application Ser. No. 09/765,713, entitled“Coating Having Macroscopic Texture and Process for Making Same,” filedon Jan. 19, 2001, incorporated herein by reference in its entirety. Inthis method, the vinyl tile is made by first mixing a polyvinylchlorideresin, plasticizer, pigments, and a high level (˜80%) of limestone(i.e., calcium carbonate) filler in a blender held at 115-135° F. Theblended powder effluent is then transferred to a continuous mixer heldat 320-340° F. for fusion (i.e. chain entanglement) of thelimestone-filled resin into thermoplastic pieces of various sizes. Thethermoplastic pieces are next sent to calendering roll operations forpartial softening and re-fusion of the limestone-filled resin into theshape of a continuous sheet having an exiting temperature of 250-270° F.and a thickness of 50-200 mils. The continuous sheet of tile base isthen carried via a conveyor belt to a nip station for lamination of aprinted design using either 2 mil thick printed polyvinylchloride filmor 0.5 mil thick printed transfer paper. The latter case involvestransferring the ink of a printed design, originally on a paper roll, tothe tile base at the lamination nip (the paper is subsequently removedwith a re-wind operation immediately following the lamination nip).

Next, the continuous sheet of tile base and laminated print layer isconveyed to another nip for lamination of a cap film, which is an ˜3 milthick polyvinylchloride film designed to protect the print layer. Boththe cap film and print layer applications rely upon the nip pressure andincoming substrate temperature for lamination; the laminating rollsthemselves are not heated. For floors requiring periodic waxing, thepolyvinylchloride cap film forms the uppermost layer of the manufacturedtile construction (an end-user applied, sacrificial wax layer being theuppermost layer in practice). However, for “no-wax” floors, athermosetting topcoat is applied as described below to the top of thepolyvinylchloride cap film during manufacture and forms a surface withsufficient durability that the need for a sacrificial wax layer iseliminated. Nevertheless, and regardless of its final designation as awaxed or no-wax floor tile, the continuous sheet of laminated tile base,print layer, and cap film is then optionally mechanically embossed.

The traditional topcoat application process for no-wax tiles involvesthe deposition and metering of a liquid film of thermally-curable orradiation-curable resin onto the tile, followed by subsequent curing ofthe resin to form a durable thermoset topcoat. The traditionallypreferred (but not exclusive) coating application method involves theuse of a curtain or roll coater to apply and meter ˜3 mil of uncuredUV-curable resin to the cap film surface of the tile. The coated, butuncured, tiles are then sent through a series of UV-processorscontaining UV lamps to induce cross-linking of the thermosetting resin,in the case where the coating is a radiation-curable coating.(Alternatively, the tiles would be heated to induce the cross-linking inthe case where the coating is a thermally-curable coating.) The backcoat is typically applied and cured using a UV processor just prior tothe application of the top coat. A thermosetting urethane back coat isalso applied with a roll-coater to balance the curling stresses impartedon the tile by the topcoat. Final processing of most no-wax tileproducts then involves an annealing process to remove processingstresses and to ensure dimensional stability.

It should be appreciated that application of the top coat may be donebefore or after the process 700 for cutting and molding the resilientfloor tile. If the top coat material is a thermoplastic material, thetop coat could be applied to the tile blank before being subject to theprocess 700 of cutting and molding. However, if the top coat material isa thermoset material, it is preferable to apply the top coat after theprocess 700 of cutting and molding to avoid micro-cracks in thecontoured edge portion of the tile.

The pallet of resilient floor tile blanks are placed into a destacker702, which feeds the blanks one at a time to conveyor belt 704 thatpasses through a pre-heated oven 706. The pre-heated oven 706 conveysheat to the blanks using heat lamps, or any other device capable ofproducing heat, as they travel through the pre-heated oven 706 tosufficiently soften the blanks for subsequent cutting and molding. Oneof skill in the art will appreciate the degree of softness requiredbased upon the composition of the tile blank. For a vinyl or vinylcomposition tile blank, it is preferable to heat the blank to atemperature of approximately 100-200° F., more preferably to atemperature of 125-135° F.±5° F., and even more preferably to atemperature of approximately 135° F.±2° F. Preferably, the pre-heatedoven 706 has a length of approximately 10 feet, and the conveyor belt704 travels through the pre-heated over 706 at a speed of approximately100′ per minute to heat the tile blank to this desired temperature.

The tile blanks are then picked-up from the pre-heated oven conveyorbelt 704 by an indexing chain-feed conveyor 708 that carries each tileblank and positions it into a cut and mold press 710. In the cut andmold press 710, each tile blank is cut and molded as described above inconnection with FIG. 6 to form a resilient floor tile having a contourededge and a print layer that extends over at least a portion of thecontoured edge, which as described above may include any contoured edge,including, for example, a beveled edge or more preferably a convex edge.

After the cutting and molding, the indexing chain-feed conveyor 708ejects the finished resilient floor tile and the scrap or frame portionout of the cut and mold press 710. Both the finished resilient floortile and the scrap or frame are then conveyed to a counter/stacker 718.The resilient floor tile and the scrap for frame are conveyed from theindexing chain-feed conveyor 708 to another conveyor belt 712, which issufficiently separated from the end of the indexing chain-feed conveyor708 to allow the scrap or frame to fall from the resilient floor tileinto a drum 714 for recycle or disposal. The finished resilient floortiles are then conveyed to a counter/stacker 716 where they areassembled into stacks, preferably stacks of 10 tiles and conveyed byconveyor belt 718 to a pallet for distribution. As noted above, in thecase where a top coat is to be applied after the cutting and moldingprocess 700, the stacked and palletized resilient floor tiles areconveyed to a coating line for application of the top coat. In addition,the stacked and palletized resilient floor tiles may also be subjectedto an annealing process before distribution.

The invention having been described, the following example is presentedto illustrate, rather than to limit the scope of the invention.

Example 1

This Example illustrates one embodiment of the present invention using aresilient floor tile comprising multiple layers. A standard uncoatedtile blank, specifically a DURASTONE tile from Congoleum Corporationwithout a top coat was used. This tile has a vinyl composition base andapproximately 82% by weight inorganic material and 18% by weight binderor total organic material content. The tile was preheated in a 6′ longconveyor oven having a belt speed of 4.8 feet per minute and a set pointtemperature of 240° F., which gave a tile temperature upon exiting theoven of approximately 145±5° F. The tile blank was then fed to the pressat which point the tile temperature was approximately 140° F. The pressutilized a die constructed to impart a convex shape to the top edge ofthe tile. The press was set to 20 tons and was closed for approximately1-2 seconds. The press temperature controller was set to 140° F., whichcontrols the top plate of the press. The bottom plate of the press waskept at room temperature. After pressing, the tile was coated with aUV-curable coating. The final size of the tile was square having thedimensions of 15 and ⅝″×15 and ⅝″. No cracks, such as micro cracks, wereobserved on the convex edge or top surface.

In a similar trial, a UV-coated tile blank similar to the one above buthaving a top coat was used. The processing was similar to that describedabove except that the press was set to 8 tons, closed for 5 seconds, andthe top plate was controlled at 220° F. The resulting tile, however,exhibited micro cracks around the convex or rounded edges. It isbelieved that the micro cracks were the result of too much stress fromthe top coat.

Example 2

This Example illustrates one embodiment of the present invention using aresilient floor tile comprising only a base. Two 16″×16″ Congoleum CXSERIES commercial tile bases having a CX-47 (earthen beige) pattern anda gauge thickness of 0.10″ were adhered to each other using double-sidedtape only for the purpose of using a thicker tile to fit the dieavailable for use in this test. The CX SERIES tile base comprises vinylacetate copolymer, melamine, stabilizer, plasticizer, limestone, andTiO₂, having a total binder concentration of approximately 17% byweight. The tile was preheated in a 6′ long conveyor oven having a beltspeed of 4.8 feet per minute and a set point temperature of 240° F.,which gave a tile temperature upon exiting the oven of approximately150° F. The tile was then fed to the press at which point the tiletemperature was approximately 140° F. The press utilized a dieconstructed to impart a convex shape to the top edge of the tile. Thepress was set to 30 tons and was closed for approximately 2 seconds. Thepress temperature controller was set to 140° F., which controls the topplate of the press. The bottom plate of the press was kept at roomtemperature. The final size of the tile was square having the dimensionsof 15 and ¼″×15 and ¼″.

Various embodiments of the invention have been described. Thedescriptions are intended to be illustrative of the present invention.It will be apparent to one of skill in the art that modifications may bemade to the invention as described without departing from the scope ofthe claims set out below. In particular, it will be clear to thoseskilled in the art that the present invention may be embodied in otherspecific forms, structures, arrangements, proportions, and with otherelements, materials, and components, without departing from the spiritor essential characteristics thereof. For example, it is to beunderstood that although the invention has been described using as anexample a vinyl composition tile, any resilient floor tile may be used.In addition, while the present invention is described as a resilientfloor tile, the tile may be used as a wall tile or for other purposes.The presently disclosed embodiments are, therefore, to be considered inall respects as illustrative and not restrictive, the scope of theinvention being indicated by the appended claims, and not limited to theforegoing description.

1-45. (canceled)
 46. A resilient floor tile, comprising: a basecomprising a binder present at a level less than 34% by weight of thebase, so that the tile has rigidity; and a decorative layer, wherein thebase, and the decorative layer together form a resilient floor tilehaving: a top surface with a contoured edge along its perimeter, whichcontoured edge has an outermost contoured surface, and a bottom surface,and further wherein the decorative layer extends over at least a portionof the contoured edge.
 47. The resilient floor tile of claim 46, whereinthe contoured edge comprises a convex edge.
 48. The resilient floor tileof claim 46, wherein the contoured edge comprises a beveled edge. 49.The resilient floor tile of claim 46, wherein the contoured edge and thetop surface are substantially free of micro cracks.
 50. The resilientfloor tile of claim 46, wherein the decorative layer extends over theentire outermost contoured surface.
 51. The resilient floor tile ofclaim 46, wherein the decorative layer extends over the entire contourededge.
 52. The resilient floor tile of claim 46, further comprising: avertical side wall extending from the bottom surface of the tile to theoutermost contoured surface so that the tile, when positioned adjacentanother tile, can be grouted.
 53. The resilient floor tile of claim 52,wherein the vertical side wall is substantially solid in that it doesnot have preformed openings or openings of predetermined shapes orsizes.
 54. The resilient floor tile of claim 46 wherein: the basefurther comprises one or more plasticizers.
 55. The resilient floor tileof claim 46 or claim 54, wherein: the base further comprises one or morepigments.
 56. The resilient floor tile of claim 46, wherein the binderis present at a level less than 28% of the base.
 57. The resilient floortile of claim 46, wherein the binder is present at a level less than 26%of the base.
 58. The resilient floor tile of claim 46, wherein thebinder is present at a level less than 20% of the base.
 59. Theresilient floor tile of claim 46, wherein the binder is present at alevel less than 18% of the base.
 60. The resilient floor tile of claim46, wherein the binder is present at a level less than 17% of the base.61. The resilient floor tile of claim 46, wherein the base isapproximately 50-200 mils thick.
 62. The resilient floor tile of claim46, wherein the tile has a thickness of approximately 4 mm.
 63. Theresilient floor tile of claim 56, wherein: the vertical side wall issubstantially solid in that it does not have preformed openings oropenings of predetermined shapes or sizes.
 64. The resilient floor tileof claim 46, which resilient floor tile is square in shape.
 65. Theresilient floor tile of claim 46, which resilient floor tile has a sizeselected from the group consisting of 9″×9″; 12″×12″; 14″×14″; 16″×16″;and 18″×18″.
 66. The resilient floor tile of claim 46, which resilientfloor tile is round in shape.
 67. The resilient floor tile of claim 46,which resilient floor tile is oval in shape.
 68. The resilient floortile of claim 46, which resilient floor tile is rectangular in shape.69. The resilient floor tile of claim 46, which resilient floor tile isa polygon in shape.
 70. A resilient floor tile, comprising: a basecomprised of about 80% inorganic material and about 20% organic binder;a protective film layer; and a decorative layer disposed between thebase and the protective film layer, wherein the base, the protectivefilm layer, and the decorative layer together form a resilient floortile having: a top surface with a contoured edge along its perimeter,which contoured edge has an outermost contoured surface, and a bottomsurface, and further wherein the decorative layer extends over at leasta portion of the contoured edge.